# What is Crystal systems ?

If you are searching about crystal system then you are on the right place . Here i am sharing with you about crystal system.To represent the type of distribution of network points in space, seven different coordinate systems are required.These coordinate systems are known as crystal systems.

There are total seven crystal system are (1) Cubic (2) Tetragonal (3) Orthorhombic (4) Monoclinic (5) Triclinic (6) Rhombohedral (or Trigonal) and (7) Hexagonal . Crystal systems are named on the basis of geometrical shape and symmetry. In 1948, Bravais described 14 lattices are sufficient to describe all crystals.These 14 lattices are known as Bravais lattices and are classified into 7 crystal systems on the basis of cell parameters.

## Seven Crystal Systems and Bravais Lattices

Seven crystal system and Bravais lattices are described below

#### 1. Cubic crystal system :

In this crystal system, the length of the unit cell edge is equal and at right angles to each other.for example a = b = c and α = β = γ = 90°.In simple cube lattice, lattice points or atoms are present at the corners of the cube. In a body-centered cube, atoms are present in the corners and an atom is completely present in the center of the cube. In the case of a face-centered cube, the atoms are present in the corners and in the center of all the faces of the cube.

#### 2. Tetragonal crystal system:

In this crystal system, two lengths of unit cell edges are equal while the third length is different. Three edges perpendicular to each other. for example a = b ≠ c and α = β = γ = 90°.Examples for tetragonal crystal system is TiO2, SnO2,

#### 3. Orthorhombic crystal system:

In this crystal system, the unit cell edge lengths are different and they are perpendicular to each other. For example a ≠ b ≠ c and α = β = γ = 90.There are four Bravais lattices in this shown below in given figure.They are simple, face centered, body centered and base focused. Examples of orthorhombic crystal systems are BaSO4, K2SO4, SnSO4, etc.

#### 4. Monoclinic crystal system:

In this crystal system, unit cell edge lengths are different. Two unit cell edges are not perpendicular, but they are perpendicular to the third edge. For example, a ≠ b ≠ c; α = γ = 90° ≠ β.This crystal system has only two Bravais lattices shown in given figure . Example of Monoclinic crystal system are CaSO4.2H2O (gypsum), Na3AlF6 (cryolite), etc

#### 5. Triclinic crystal system:

In this glass system, the length of the edge of the unit cell is different and not perpendicular. for example a ≠ b ≠ c and α ≠ β ≠ γ ≠ 90° and all angles are different .Examples for triclinic crystal system are K2Cr2O7, CuSO4. 5H2O, etc

#### 6. Rhombohedral [ Trigonal] crystal system:

In this crystal system, unit cell edges are all lengths equal. The angles between the axes are the same but other than 90°.i.e. a = b = c and α = β = γ ≠ 90°.Examples for Rhombohedral crystal system are As, Bi, Sb, etc

#### 7. Hexagonal crystal system:

In this glass system, two sides of the unit cell edge length are equal and the angle between these edges is 120 °. These two edges are perpendicular to the third edge and are not the same length. Bravais lattice is primitive only

### Biasing of p–n Junction | Forward and Reverse-biased |

Biasing the p-n junction means applying some external voltage to both sides of the p-n junction. Reverse-biased junction and forward-biased junction are two types of biased junction. You should have also good understanding of  N-Type and P-Type Semiconductor before moving towards this topic.

Biasing of p–n Junction Biasing of a p–n junction means uses of some external voltage across the two sides of the p–n junction. It is divided into two groups
Forward-biased junction : When the p-side of junction  is connected to the positive terminal of a battery and the n-side of junction is connected to the negative terminal, the p–n junction is said to be a forward-biased junction. Reverse-biased junction :If the positive terminal of the battery is connected to the n-side of junction and the negative terminal on the p-side, the p–n junction is said to be a reverse-biased junction.Now we will see about forward and reverse-biased junction in detail.
Related TopicBonding in semiconductors and Bond m…

### Know How to study science,Tips For Final Board Exam

If you are search about how to study science so i am going to share with you some tips that help you to study science in effective way. In this post, we are going to see what you should keep in mind while studying science. Because of which you can complete the syllabus of your science subject in the least time and comfortably and can  study  well with full concentration. So I will tell you five such tips with which you can study science comfortably.

How to study scienceWhether you are a student of class 10, whether in class 12 or any class, while studying science, these five tips will help you to get good score in science as well as improving your interests in science .

Goal Setting : By Goal Setting, I mean that when you sit for study, you have to set this target that today I will read so much chapter or today I will get up after reading so much content.This thing will do the work of positive motivation and will push you that we have to study till then. Until my target is achieved.
Rea…

### 10 Benefits Of Study Electrical Engineering That May Change Your Perspective.

We see applications of electricity all around us.Today we will discuss about the need to study electrical  engineering .We observe the presence of electricity around us. This is really amazing and it is also interesting to know how mankind can power its use. All electronic and electrical products operate on electricity.  Be it your computer system, cell phone, home entertainment system, lighting, heating and air conditioning system - all are examples of electrical applications. The application of electricity is infinite and often extends beyond our imagination.

The need to study electrical engineering We have need to study electrical engineering because of following reason .Which is discussed below in given points.
1.It help you in getting your first electrical engineering job is easy :Demand of electrical engineering is emerging day to day. It will definitely help you to get get your first job in the field of electrical engineering.If you have good knowledge and a certificate you can eas…